A sauna heating unit irrespective of what type of power source is used, electricity, wood, gas etc. generates owing to the chimney effect or a fan a very hot air stream (200.degree.-600.degree. C.) straight and somewhat obliquely upwards. This hot air does of course heat the ceiling of the sauna room, which usually is made of a burnable material, e.g. wood. For preventing the ceiling from being damaged, discoloured, carbonized and/or ignited or smelted if it is made of a plastics material it has hitherto been necessary to build the sauna rooms with such a large distance between the heating source and the ceiling, that these risks do not occur.
This involves either that a relatively large ceiling height is required, which means that there can be problems finding a space for building the sauna, or the heating effect has to be reduced. International security regulations (CEE) for saunas state that the ceiling height may not be less than 190 cm. Since most houses nowadways are built without a basement many people wish to build their saunas on the upper floor, which often has a pitched roof and/or low ceiling heights.
In the Swiss patent specification No. 469.484 is shown a plate of a heat-resistant material attached close to the ceiling above a sauna heating unit, said plate guiding the stream of hot air out towards the sauna room. This plate must owing to the great distance from the sauna heating unit, have a very large area in order to be effective and besides that it means a complication at the building of the sauna room.
In the Swedish patent specification No. 359.026 is shown a sauna heating unit with a hinged flap which when raised automatically returns to its position substantially covering the upper end of the aggregate. The only purpose of the flap is to prevent heat radiation towards the ceiling at normal ceiling heights in the sauna room for sauna heating units without a stone store. It would not serve any purpose at the generation of steam because the flap would cover a possible stone store and make the pouring of water over the stones impossible.
In the Norwegian patent specification No. 72.084 a wood heated sauna oven is shown, immediately above which a shield arranged to guide the hot air downwards is attached. It is true that the heat radiation towards the ceiling is reduced, but no significantly increased effect of the steam generated when pouring water over the heated stones is achieved.